Many types of transaction cards (account cards, identification cards and the like) have been used by individuals to gain access to account files in a bank or similar institution to gain access to secure areas, or to initiate some similar transaction enabling them to access otherwise restricted information stored in the institution. Not infrequently, the person using the card is not the person to whom the card was issued (i.e., not an authorized user of the card), but a person who has found, stolen, or manufactured (perhaps duplicated) the card with the intent to use it illicitly.
Heretofore, relevant information such as account number or code, employee number, social security number and the like, has been included on the card such as by embossing, magnetically or optically encoding on the card, or the like. A card of this type, and a system which utilizes such a card, are shown, for example, in U.S. Pat. No. 3,862,716 entitled "Automatic Cash Dispenser and System and Method Therefor", issued Jan. 28, 1975 to Robert Black and Christopher Hall.
Because of the dire consequences usually occasioned by the breach of the security of such a card-utilizing system by an unauthorized card user, a more secure card and system which would make the probability of a breach more remote would be highly desirable. A card and a system for utilizing the card are needed which actively contribute to the security process by securing data entered into the system, rather than merely passively reproducing data which is prerecorded on the card.